Low Key Design Because the m80 looks stock, your BMW and valuable possessions remain safe.	No Space Sacrifice Provides revolutionary performance without bulky equipment overtaking ANY of the already limited trunk space in your Z3 / M Roadster.
Tight, Articulate Bass Rigid aluminum cone 8" subwoofer virtually eliminates distortion yielding accuracy, realism, and musical reproduction that is unprecedented from an automotive subwoofer system.	Astonishing, Authoritative Output Combines extremely efficient subwoofer design with stout amplification. Result: a deep, astounding bass foundation that extends effortlessly to frequencies most subs never reach.
True Fidelity State of the art amplification and signal chain insures totally transparent link from source unit to subwoofer for unmatched purity, precision, clarity, and openness.	Rattles? What Rattles? Utilization of pre-existing mounting points and isolation techniques means that the chances of your new subwoofer system rattling are slim to none.
Extremely Low Weight Sub-20lb. weight for entire system. You won't notice it's there.	Do-It-Yourself Installation Includes step-by-step instructions with photos. Requires only 7 wire connections. An afternoon with your BMW and basic tools is all you'll need.
100% Complete System Includes absolutely everything you need: amp, subwoofer, installation hardware, wiring. Just buy and install.	Performance Guaranteed Unconditionally guaranteed to exceed all your expectations or your money back. You get 30 days to try our products, and if you're not totally happy, send them back for a refund.

the how and why of bass in your BMW

Fully 1/3rd of all recorded music is below 80Hz (this is called bass!) Almost no interior component speaker can reproduce sound below 80Hz without high levels of distortion (some CAN reach to around 60Hz, but that's really the lower limit). The cheap paper drivers BMW uses in their audio systems are certainly no exception to this rule.

Why? High output bass production requires that a speaker physically moves a great deal of air relative to what's required for higher frequencies. This air movement is accomplished in either or both of the following two ways:

• High Excursion: Excursion refers to how far a speaker can move in or out from its resting state. The smaller the speaker, the larger the amount of excursion required to produce bass output -- and vice versa. However, a small driver with high excursion is far less efficient than a larger driver with lower excursion (requiring TONS of power from the amplifier) and is very impractical in a car audio situation due to the space required in front of such a driver to accomodate the movement. (It's also difficult to design a very high excursion driver that remains accurate at the limits of its movement).
  
  
• Large Cone Surface: As the cone surface area of a speaker increases, the more air the driver can move -- and the more efficient a driver becomes relative to a speaker with smaller cone surface area. However, the additional mass of such a driver requires more power and a more stout motor structure (the components that control the speaker cone surface) to keep the driver controlled and accurate.

Both solutions do require substantial power output from the amplifier driving them, but power can be expensive. For cost savings reasons, manufacturers will produce a larger coned driver out of lightweight material (i.e. paper) to minimize power requirements. Unfortunately, the resulting lightweight subwoofer is flimsy, and when combined with low power yields muddy, fuzzy bass at moderate volumes and distortion at high volumes. This is PRECISELY the case in your Z3 or M Roadster.

And if you don't have the Premium System, because your stock amp and speakers (and even high quality component speakers and an aftermarket amp) are small in size, share the same lightweight construction, and are low in power, you'll get the same fuzzy bass, just less of it.

And so, an effective, high power subwoofer solution is needed. But with the BSW m80, it doesn't have to come with sacrifices.

absolutely everything you need is included!

The BSW m80 subwoofer system is a 100% complete kit. All you need is basic tools!

RoadsterSound Model 80 Subwoofer Enclosure & Mounting Hardware	BSW by Alumapro 8" Alusonic EX Aluminum Cone Subwoofer with Protective Grille
Rockford Fosgate P200-2 Amplifier (230W @ 4 Ohms)	All required installation hardware, wiring, and accessories
Detailed step-by-step instructions with photos	Performance Guaranteed Unconditionally guaranteed to exceed all your expectations or your money back.